Carbon emissions from fossil fuel use in the transport sector are rising faster
than those from any other sector (Price et al., 1998). The transport modes responsible
for most of the growth are car travel, road freight, and air transport.

Vehicular air pollution is a major environmental problem in many large urban
centres in both developed and developing countries. Although urban air quality
in developed countries has been controlled to some extent during, the past two
decades, in many developing countries it is worsening and becoming a major threat
to the health and welfare of people and the environment (UNEP, 1992).

Chapter 3 notes the existence of a range of technologies
whose use in cars could substantially reduce emissions, including lightweight
materials, gasoline direct injection engines, electric hybrid drive-trains,
and fuel cell-electric drive-trains. Considerable and unexpected progress has
been made in commercializing some of these technologies since the SAR. Chapter
3 also reviews studies that estimate the socioeconomic potential for energy
efficiency improvements. The rapid emission growth from the sector, despite
the considerable apparent mitigation potential, is mainly a result of a continuing
increase in demand for mobility of people and goods. The energy intensity of
personal travel is near-constant or increasing in many countries, with increasing
use of sports utility vehicles and people carriers, and rising vehicle weight
and power in most categories of vehicle (ECMT, 1997; Davis, 1999).

In addition to energy efficient technologies, IPCC (1996, Chapter 21) noted
an extensive range of options for reducing GHG emissions, including the use
of alternative fuels, public and non-motorized transport, and changes in transport
and urban planning.